Hydraulic system



SephZ, 1941. J. E. HOLVECK HYDRAULIC SYSTEM Filed Dec .v

28, 1938 3 Sheets-Sheet 1 Joseph E- Hulveck l VENTOR ATTORNEY Sept. 2, 1941. J. E. HOLVECK HYDRAULIC SYSTEM Filed Dec. 28,, 1935 5 Sheets-Sheet 2 k QM w v fin HM .WR E a m o fin O O O O mm m Hi H I MHH E n O@O J74 k v EM A O O m O 0 LHI n o 0 4 aw JFW S Y Y Y Q a m a 5 v 3 nu q J. E. HOLV ECK 2,254,848

HYDRAULIC SYSTEM Filed Deq. 28, 1938 3 Sheets-Sheet 3 Sept. 2, 1941.

.luseph E. Hulvack INVENTOR ATTORNEY Patented Sept. 2, 1941 HYDRAULIC SYSTEM Joseph E. Holveck, Grafton, Pa... assignor to Worthington Pump and Machinery Corporation, Harrison, N. J., a corporation of Delaware Application December 28, 1938, Serial No. 248,069

4 Claims. This invention relates to hydraulic systems and more particularly to means in a hydraulic system for absorbing shocks to the system and pump caused by sudden and abrupt variations in' the discharge flow from the pump or pumps, and for purposes of'illustration and explanation the present application refers to a hydraulic decoking system and apparatus used in the oil refining industry for removing coke from the coke or reaction chambers employed in a petroleum refinery.

In hydraulic decoking systems such as that shown and described in the pending application filed by William F. Court, Serial No. 191,685, the hydraulic method of decoking consists of cutting the coke from the .coking chambers by highimpact-producing water jets which are projected from suitable nozzles into the coke bed for cutting the coke in layers and freeing such layers from the walls of the coke chamber.

In carrying out the decoking operation, it is frequently necessary to vary the water flow to the nozzles, and stop and start it, causing sudden variations in the discharge flow from the pump ranging from zero to maximum. Such sudden interruptions to the flow of water to. the nozzles result in hydraulic shocks to the system and par-v ticularly to the pump which shocks cause excessive wear, upset the balance and generally affect the decoking system disadvantageously.

It is an object of the present invention to provide means operable simultaneously with variations in the fiow of water through the system to the nozzles, which will minimize the shocks to the system due to'sudden interruptions to the flow or too rapid variation in the discharge flow from the pump, and consequently relieve the system of the detrimental effects of such shocks.

With these and other objects in view, as may appear from the accompany specification, the invention consists of various features of construction and combination of parts which will be vfirst described in connection with the accompanying drawings, showing a hydraulic decoking system embodying the invention, and the features forming the invention will be specifically pointed out in the claims.

In the drawings:

Figure 1 is a diagrammatical perspective view of the apparatus employed in a hydraulic decoking system.

Figure 2 is a view partly in side elevation and partly in section of the mechanism for relieving the shocks to the pump and system.

Figure 3 is a longitudinal horizontal section through the shock relieving mechanism.

Figure 4 is a vertical section on the line 4-4 of Figure 2. p

Figure 5 is a detailed section through a speed control valve employed in the structure.

Referring more particularly to the drawings,

the hydraulic decoking system above referred towhich is employed for removing the coke from the coking chambers, indicated at I, 2, 3 and 4 of Figure 1 of the drawings comprises a hydraulically operated boring tool 5 which is shown diagrammatically in the coking chamber 4. This boring tool 5 is utilized for boring a hole through the bed of coke indicated at A in the chamber and which receives its actuating pressure water from a high pressure pump 6 through a series of piping l which may have the necessary universal joints indicated at 8 and 9 and various lengths indicated at H) to permit -it to pass downwardly through the coke A. In Figure l of the drawings two pumps are shown, one of which is normally used as a standby pump.

After the boring tool 5 has passed through the coke bed A, boring a central hole H therethrough as shown in the coke chamber 3, a cutting nozzle assembly indicated at I2 is employed which is moved upwardly through the coke .bed, in steps, cutting the coke in layers, as indicated at B. The layers of coke are cut by high-impactprbducing nozzles broadly indicated at I3, while the layers are freed from the walls of the re: spective coke chambers by the upturned highimpact-producing nozzles M. The cutting nozzle assembly I 2 is connected to the piping system' H) and I in place of the boring tool 5 during the cutting operation.

The coke cut from the coking chambers falls into any suitable receptacle, which is shown in Figure -1 as a coke carv l6, while the water flows therethrough to a sump H, from which it passes to settling tanks l8. The suction of the pump 6 is connected to the settling tanks I8 through suitable piping l9.-

The operation of the decoking apparatus r quires frequent sudden stopping of the flow of water bothfrom the boring tool 5 and from the cutting nozzle structure l2, and it is of course necessary to have the high pressure water in sufficient quantity always available when the supply to the nozzles is again opened, and therefore it is necessary that the pump 6 be continuously operating to supply the water at sufficient pressure and in suflicient quantity to efliciently operate the system. The sudden variations in the discharge flow of the water from the pump 6 sets up accelerated forces in the system and particularly in the pump structure, which accelerated forces cause both axial and radial thrusts on the pump parts, tending to unbalance the pump and cause excessive wear thereon. To overcome the detrimental effects of the excessive shocks on the system a shock load diminishing apparatus is provided and consists broadly of a by-pass 20 between the discharge of the pump 6 and its suction.

The discharge ious nozzle connections has a cut-off valve 2| mounted therein which is of the balanced piston type so that it will normally be held closed by the pressure of the discharge water flowing from the pump 6. The valve piston 22 of the valve 2| is moved into open position and held therein by means of a valve actuating mechanism 23. The valve actuating mechanism 23 comprises a cylinder 24 having a piston 25 mounted therein for reciprocatory movement. The piston 25 is operated in the cylinder 24 by pressure fluid from. any suitable source, preferably pressure from the air system (not shown) of the refinery. The pressure fluid from the air system passes through a three-way valve structure 26, of any approved constructon, which is operated by a solenoid 21.'

The solenoid 21 is connected with a control switch 28 located in any convenient position so that the operator of the decoking system may at will operate the switch 28, to in turn operate the solenoid 21 and three-way valve 26 to control the delivery of pressure fluid to the cylinder 24. The pressure fluid enters the three-way valve 26 through the supply line 29 and passes from the three-way valve into the cylinder 24, either through the pipe 30 or the pipe 3|, on whether the control switch 28 is operated to cut off the supply of water from the pump or to open the supply of Water from the pump to the nozzles.

When the supply of water to the nozzles is to be opened, the pressure fluid passes through the pipe 30 into the cylinder 24 and moves the piston 25 to the left in Figures 2 and 3 of the drawings, moving the actuating rod 32 into engagement with the abutment 33, which is mounted on the rod 34 of the valve 22. This forces the valve 22 off its seat and opens the discharge line from the pump, and at the same time permits the valve piston 50 to be seated to cut off flow of fluid through the by-pass 20 When the supply of water to the nozzles is cut off and the control switch 28 is operated the pressure fluid passes from the three-way valve 26 through the pipe 3| and forces the piston 25 to the right, in Figures 2 and 3 of the drawings. The movement of the piston 25 to the right moves the operating abutment rod 32 out of engagement with the abutment 33, and the valve 22 is forced against its seat 31 to cut off the flow of water to the nozzles by the unbalanced pressure due to the differential area between the valve piston 22 on the one hand and of the abutment 39 and the stem. 22' on the other hand. The stem 22' has a hole or passage 23' drilled therein from the inlet side of the valve piston 22 to the chamber 24'. As the piston 25 moves to the right it moves the abutment rod 38, which is also carried by the piston 25 into engagement with the abutment 39 carried by the piston rod 4|] of the valve piston 50 of the by-pass controlling valve structure and moves the piston 50 off its seat, opening the by-pass 20 around from the discharge of the line'l from the pump to the vardepending pump to its suction, permitting a continuous operation of the pump and relieving the pump of the detrimental action of any accelerated forces which would be set up by the abrupt variation in the rate of discharge from the pump.

The valve rod is provided with a passage 5|, which opens from the inlet side of the valve piston 50 into the chamber'52' at the end of the rod, so that upon opening of the valve 2| the valve 5| will be closed by the unbalanced pressure due to the differential area between the piston valve 5| and rod 50, in the same manner as the valve 2| is closed.

The three-way valve structure 25, which as previously stated may be of any approved construction, opens the left-hand end of the cylinder 24 to the exhaust when the right-hand end of the cylinder is opened to receive pressure fluid. and vice versa.

Speed control valves 53 are mounted in the pressure fluid supply lines to the cylinder 24 to control speed of flow of the pressure fluid to the cylinder, and consequently to control the speed of operation of the piston 25 and of the valves 2| and 5| so that these valves will operate at the proper and desired rate of speed to relieve the pump and the water system of the decoking apparatus of excessive shocks caused by the opening and closing of the discharge line to the nozzles.

These speed control valves 53 may be of any approved construction which may be purchased upon the open market, and a detailed section of one type of such valve is shown in Figure 5 of the-drawings. 1

As shown in Figure 2 of the drawings, the abutment operating rods 32 and 38 are constructed so that their lengths may be adjusted to insure proper operation of the valves 2| and 5|, in synchronism and at the proper times. The structure which permits of such adjustment is quite simple, consisting of a threaded rod 55 threaded into the end of the rod and located in adjusted position by means of a lock nut 56. The head 5'! on the threaded rod 55 serves as the abutment surface for contact with the abutment members 33 and-39 respectively.

While in the foregoing description and in the drawings the invention is described and shown in connection with a hydraulic decoking system, it is to be understood that it may be employed in any hydraulic system embodying similar conditions of abrupt variation in the discharge flow of the pump, without departing from the spirit of the present invention.

It will be understood that the invention is not to be limited to the specific construction or arrangement of parts shown but that they may be widely modified within the invention defined by the claims.

What is claimed is:

1. In a hydraulic system, means for relieving a 2 pump having a suction and discharge line of sudden shocks due to variation of load thereon including a by-pass between the suction and discharge lines of the pump and means controlling said by-pass, said means including a valve interposed in said by-pass, a second valve interposed in the discharge line of the pump, said valves being held closed by pressure of fluid in the respective lines, and pressure actuated means for opening said valves.

2. 'In a hydraulic system, means for relieving a pump having a suction and discharge line of sudden shocks due to variation of load thereon including a by-pass between the suction and discharge lines of the pump and means controlling said by-pass, said means including a-valve interposed in said by-pass, a second valve interposed in the-discharge line of the pump, said valves provided with difierential areas, said valves provided with passages to permit fluid under pressure to flow past the valve and act upon the greater of said difierential areas to hold the valve closed by pressure of fluid in the line, and pressure actuated means operated independently of the operation of the pump to open and hold open one of said valves while the other valve is closed.

3. In a hydraulic system, means for relieving a pump having a suction and discharge line of sudden shocks due to variation of load thereon including a by-pass between the suction and discharge lines of the pump and means controlling said by-pass, said means including a valve interposed in said by-pass, a second valve interposed in the discharge line of the pump, said valves provided with difl'erential areas, said-valves provided with passages to permit fluid under pressure to flow past the valve and act upon the greater of said differential areas to hold the valve closed by pressure of fluid in the line, a pressure actuated piston, a valve actuating rod carried by said piston, abutments connected to said valves for engagement by said rod, said piston movable to open and hold open one of said valves and permit closing of the other valve.

4. In a hydraulic system, means for relieving a pump having a suction and discharge line of sudden shocks due to variation of load thereon including a by-pass between the suction and discharge lines of the pump and means controlling said by-pass, said means including a valve interposed in said by-pass, a second valve interposed in the discharge line of the pump, said valves provided with difierential areas, said valves provided with passages 'to permit fluid under pressure to flow past the valve and act upon the greater of said diiferential areas to hold the valve closed by pressure of fluid in the line, a pressure actuated piston, a valve actuating rod carried by said piston, abutments connected to said valves for engagement by said rod, said piston movable to open and hold open one of said valves and permit closing of the other valve or movable into position to permit closing of both of said valves, and means controlled independently of operation of the pump for controlling delivery of operating pressure fluid to said pressure actuated piston.

JOSEPH E. HOLVECK. 

